Fritz K. Oser is best known for his work in the fields of religious and moral development, educational psychology, and political education. This entry highlights his contributions in the fields of spiritual and moral development.

Born in1937 in Switzerland, Fritz Oser studied philosophy at the University of Basel under Karl Jaspers and educational psychology, developmental psychology, and systematic pedagogy at the University of Zurich where he received his Ph.D. in 1975. His postdoctoral work with Lawrence Kohlberg at Harvard University prepared the way for the construction of his theory of religious development. Oser's theory argues that religious development is universal and occurs in stages. Each stage represents an integration of the stages below and is a qualitatively different way to think about religious questions. Religious development usually happens due to a confrontation with a problem that cannot be solved using one's current stage of religious judgment. This development happens independently of the content of a specific religion. The theory is similar to James Fowler's theory of faith development but has a stronger focus on how people define their relationship to God or what they take to be Ultimate (God). Oser (together with Paul Gmunder) also developed a stage theory of religious judgment. This theory identified patterns of judgment used in concrete situations, particularly in situations calling into question one's relationship with God or what one takes to be Ultimate- such as when tragedy strikes or when there is a momentous decision to be made. These patterns are defined by bipolar dimensions needing to be coordinated-such as transcendence versus immanence, holy versus profane, trust versus absurdity, and freedom versus dependency. At lower stages, people see only one polar dimension at a time. At higher stages, people connect polar dimensions such that, for example, the Ultimate is seen as both transcendent and immanent. Using information about how people differentiate and coordinate polar dimensions central to making religious judgments, Oser constructed five stages of religious judgment to capture overall development: In stage one, the orientation is toward religious heteronomy. God is understood as active but intervening unexpectedly in the world. Humans merely react to God's interventions. In stage two, the orientation emphasizes reciprocity. Even though the Ultimate is seen as being all powerful, individuals are seen as being able to influence God, for example, through prayer and by making promises. In stage three, the orientation emphasizes autonomy of the self. Here, the influence of the Ultimate Being is considerably reduced as individuals stress their own personal autonomy and responsibility in making decisions. People in stage four perceive the Ultimate in ways reminiscent of Tillich's phrase "The ground of all being." At stage four, an indirect, mediated relationship with God emerges. Finally, at stage five, the orientation emphasizes religious intersubjectivity and autonomy. The higher the stage, then, the more individuals experience themselves as autonomous and free while also experiencing themselves as dependent upon and connected to God or whatever is taken to be Ultimate. Oser's related line of research has been on moral development. Oser and his associates (e.g., Wolfgang Althof) have written several books and articles in which they critically evaluate Kohlberg's theory and address such central issues as whether moral development can be captured by structural analysis only and whether there are gender differences in moral reasoning.

The work on moral development has made its most important contribution by distinguishing two processes by which moral development proceeds. According to Oser, moral development can result from wrestling with moral dilemmas, hypothetical or real, and/or from living in a just and democratic environment. In the second case, individuals (children) develop morally as they learn to deal with the many naturally occurring conflicts between themselves and others. Fritz Oser's contributions to our thinking about religious and moral development have been considerable. But like so many other major researchers, his additional contribution has been to support the development of other researchers and to help establish a community of researchers dedicated to better defining the field. Oser's contribution, then, cannot be measured simply in terms of his articles, books, and theories. It needs also to be measured in terms of his being a community builder.